NASA Ames / Mars Society / CMU FIELD PETROGRAPHY EXPERIMENT

November 25, 1998

Human missions to Mars will have to include substantial capabilities for
doing science analysis in-situ, i.e. on Mars, since shipping many rock
samples
back to Earth will be impractical. A key analytical capability will
be to be able
to do petrographic analysis and to share petrographic information with
scientists back on Earth. By examining rocks in thin section, definitive
information can be derived about their nature, origin, history, and
possibly fossil content. The 1998-1999 field season of the NASA/CMU
Robotic Antarctic Search for Meteorites Program will be an opportunity
to conduct the first tests of a remote field petrology kit
developed by NASA Ames and the Mars Society.

Because of the dust generated and the need to protect samples from
contamination, rock-cutting on Mars will probably be an EVA
(extravehicular activity) or an activity conducted in an isolated environment
within a surface habitat. In the current Mars Society "Mars Arctic
Research Station" (M.A.R.S.)
design, a glove case is envisioned in which rock cutting and thin section
preparation
will be done through a glass bay. An astronaut would be inside the
habitat's
shirt-sleeve environment and would manipulate the samples to
be analyzed
through pressurized gloves extending into the bay. The samples, if
not
actually outdoors, may be kept in the bay under an environment close
to that prevailing outside.

The field petrography experiment package brought to Patriot Hills,
Antarctica, will allow the rocks studied with the Nomad rover's complement
of instruments to be characterized in detail while
the Nomad team is still in Antarctica. The kit will allow the team
to cut
rocks in the field, polish them, make thin sections, look at these
under a
petrographic microscope, capture interesting microscope views on video,
and
share the data with collaborators back at NASA Ames and at the Mars
Society
through the Internet. Rapid feedback and any needed science support
would
then be available to the field team.

The field petrography kit comprises a "Gryphon" electric diamond band
saw
cooled with propylene glycol (antifreeze) by capillary contact, a "Hi-Tech"
diamond grinder/polisher lubricated by propylene glycol, a Ward's petrographic
microscope, and a Mobile Science Workstation (MSWS) developed
by NASA Ames's Rick Alena of the Intelligent Mobile Technologies group
and his team. Rock-cutting and polishing will be done outdoors at Patriot
Hiils while the operator uses thick neoprene gloves to simulate the
mobility
restrictions of spacesuit-type gloves.

The field petrography kit presently tested will be further developed
during
upcoming field seasons of the Haughton-Mars Project at the Haughton
impact crater,
Devon Island, Arctic Canada. While the current design of the field
petrography kit is
human-operated, ways to automate the process in the context of a human
mission to Mars will be examined in consultation with the Carnegie
Mellon University
Robotics Institute field team.

Support for this experiment was provided by
NASA Ames Research Center
The Mars Society
The Robotics Institute, Carnegie Mellon University
Fuerza Aerea de Chile (FACH), Chile
and is gratefully acknowledged.